This issue manifests as being correctly enrolled with CryptAuth and having other RemoteDevices available via CryptAuthDeviceManager, but not having the local device be present in the list returned by CryptAuthDeviceManager::GetSyncedDevices(). One consequence of this: the local device can't fetch its own beacon seeds :(

It seems that device sync either happens before enrollment, or the two are racing. If I check chrome://proximity-auth, I see:

Enrollment:  last success: 5/25/2017 5:01:24 PM.
Device sync: last success: 5/25/2017 5:01:23 PM.

As you can see, device sync occurred 1 second *before* enrollment, so there's no way for the devices pulled down to include the local device.

Proposed solution: Tweak ChromeCryptAuthService to only call CryptAuthDeviceManager::Start() at first, and then call CryptAuthEnrollmentManager::Start() when CryptAuthDeviceManager::OnEnrollmentFinished() is called. Tim, can you weigh in on if this is a decent solution?